Light-emitting semiconductor device with open-bypass function

Abstract

This invention discloses a light-emitting semiconductor device with open-bypass function, which comprises two terminals providing a current, at least one LED unit and a bypass switch. Electrodes of the LED unit and the bypass switch are properly connected to the terminals, so that the bypass switch will provide an alternative path for current flowing through if the circuit of the LEDs unit between two terminals is open.

1 . A light-emitting semiconductor device with open-bypass function, comprising: 
 a first terminal;    a second terminal;    at least one LED unit each comprising one or more LED die, a first electrode and a second electrode respectively connected to the first and the second terminals; and    a bypass switch comprising a third electrode and a fourth electrode respectively connected to the first and the second terminals;    wherein    the bypass switch will be in an “Off” state without current flowing through if the LED unit can be lit by applying a current to the first and second terminals; or    the bypass switch will be in an “On” state for conducting the current if the LED unit is in an open circuit.    
   
   
       2 . The light-emitting semiconductor device of  claim 1 , wherein the first and the second terminals are attached to a substrate by wire bonding and surface mount technology.  
   
   
       3 . The light-emitting semiconductor device of  claim 1 , wherein the LED unit will generate a first signal delivered to the third electrode and a fourth of the bypass switch as being in an open circuit; and 
 the bypass switch will be in the “Off” state if the first signal is lower than a predetermined voltage; or    the bypass switch will be triggered to enter into the “On” state if the first signal is equal to or higher than the predetermined voltage.    
   
   
       4 . The light-emitting semiconductor device of  claim 1 , wherein the bypass switch is formed as an integrated circuit and comprises: 
 a voltage detection circuit with an anode, a cathode and a gate, wherein the anode and the cathode are respectively connected to the third electrode and a fourth of the bypass switch; and    a switch circuit with an anode, a cathode and a gate, wherein the anode and the cathode are respectively connected to the third electrode and a fourth of the bypass switch, and the gate is connected to the gate of the voltage detection circuit;    wherein the voltage detection circuit can generate a second signal according to the detected voltage, and the second signal will drive the gate of the switch circuit through the gate of the voltage detection circuit and therefore turn on the switch circuit into the “On” state.    
   
   
       5 . The light-emitting semiconductor device of  claim 4 , wherein the switch circuit comprises a PNPN thyristor with a P anode and an N cathode respectively connected to the anode and the cathode of the switch circuit.  
   
   
       6 . The light-emitting semiconductor device of  claim 4 , wherein the switch circuit comprises a first bipolar junction transistor with a first emitter, a first base and a first collector and a second bipolar junction transistor with a second emitter, a second base and a second collector; wherein: 
 the first emitter and the second emitter are respectively connected to the anode and the cathode of the switch circuit;    the first base is connected to the second collector; and    the first collector is connected to the second base.    
   
   
       7 . The light-emitting semiconductor device of  claim 4 , wherein the switch circuit comprises a first MOSFET with a first source, a first gate and a first drain and a second MOSFET with a second source, a second gate and a second drain; wherein: 
 the first source and the second source are respectively connected to the anode and the cathode of the switch circuit;    the first gate is connected to the second drain; and    the first drain is connected to the second gate.    
   
   
       8 . The light-emitting semiconductor device of  claim 4 , wherein the switch circuit comprises a bipolar junction transistor with an emitter, a base and a collector and a MOSFET with a source, a gate and a drain; wherein: 
 the emitter or the source is connected to the anode or the cathode of the switch circuit;    the base is connected to the drain;    the collector is connected to the gate.    
   
   
       9 . A light-emitting semiconductor apparatus, comprising a plurality of the light-emitting semiconductor devices of claim I and a current source to construct a series or parallel circuit.